LONDON (Reuters) - TalkTalk (>> Talktalk Telecom Group PLC) notched up the fastest growth in broadband subscribers in four years in its second quarter, as a net 15,000 new subscribers signed up for deals that increasingly include mobile calls and television.

TalkTalk has been pushing its TV offer, but in the last quarter broadened its promotions to include high-speed fibre broadband and mobile.

Chief Executive Dido Harding said she expected customer growth to accelerate in the second half.

"We are seeing a continuing, and if anything accelerating, trend towards triple and quad play bundling," she said on Tuesday, referring to the packages that throw in high-speed fibre broadband, mobile, and television.

"More than a third of customers are now taking TV and just under 10 percent of our base is taking mobile."

Some 115,000 customers took TalkTalk's TV service in the quarter, a slowdown from the 185,000 additions in the first, but still more than its rivals BSkyB (>> British Sky Broadcasting Group plc), Virgin Media (>> Liberty Global PLC) and BT (>> BT Group plc) put together, Harding said.

Britain's telecom and broadband operators are preparing for a shift in the market as customers take more services from a single company, a trend that is expected to accelerate next year when BT re-enters the consumer mobile market.

Mobile operator Vodafone (>> Vodafone Group plc), which provides the network for TalkTalk's mobile service, said on Tuesday it would launch a British home broadband and TV offer.

Harding, however, said TalkTalk had a clear proposition across all services that customers could tailor with one-off purchases, like movies.

"Our results are showing there really is space for a value-for-money quad play provider," she said.

TalkTalk's revenue increase by 3.6 percent to 437 million pounds in the quarter, while core earnings for the first half grew 44.7 percent to 110 million pounds.

It said it expected to deliver revenue growth of at least 4 percent and "strong growth" in core earnings for the full year.

Its share were trading down 3.6 percent at 285.9 pence at 10:43 GMT. Analysts at Citi said the group had left a lot to achieve in the second half to reach its 4 percent growth target.

(Editing by Karolin Schaps and Clara Ferreira Marques)

By Paul Sandle